The present invention relates to a process for manufacturing an ornamented part wherein a multilayer sheet of ornament with a back of foam is brought onto a support portion, the sheet of ornament comprising a back of foam and surrounding at least in an edge region of the support portion by the ornament, and to a device for carrying the process into effect.
For the manufacture of parts with an upper surface that is ornamented, in particular by an ornamental material, the assembly must be worked, despite drawbacks, with a layer of foam. The part thus obtained must, in particular, have a good appearance when the foam thickness is comprised between 0.5 and 5 mm. For optical considerations, an acute angular passage or a transition with a maximum radius of 2 mm must remain on the limiting portions of the parts in the edge outer portion. This implies for the portion that, in the edge region, a bending by 90xc2x0 or a bending back by 180xc2x0 is necessary. In case the foamed underlayer covers the edges respectively in the lining region, the foam thickness will generate a greater or lesser radius, which is not desired if it is required to obtain an excellent lining completion.
The invention teaches a process and a device for manufacturing an ornamented part on which is brought a multilayer ornament formed of a back of foam and a sheet of ornament, on a support portion of the part, that it surrounds in the edge region with an acute angle or a maximum radius of 2 mm.
The process according to the invention for the manufacture of a part which is ornamented by applying an ornamental material comprising a back of foam is characterized in that:
in a first step, the ornament is brought onto the part and is maintained in the edge region;
then, in a second step, the foam thickness is reduced by heating in corresponding zone of the edge, then stretched ; and
in a third step, the ornament assembly or the projecting sheet of ornament is fixed onto the part.
Preferably, the back of foam has a thickness comprised between 0.5 and 5 mm. Advantageously, the ornament or its projecting portion surrounds the edge region of the part with a maximum radius of 2 mm.
For enabling to make the lining, the foam thickness in said zone is reduced or removed by a laser and/or high frequency radiation and/or by heating and or stretching.
It is possible to provide that the ornament, or its projecting portion, in particular in the region of the angles and/or of the outline, and/or in the outline zone of the support portion of the part is stretched before and/or during the third step.
It may be provided that a suction is applied onto the back of foam on the portion to be lined, at the opposite of the ornament, and/or that a pressure is applied on the side of the sheet of ornament, at the opposite of the foam, in the third step.
Said zone, that surrounds the edge region may be stretched before the second or third step. Thus, it is possible to provide that said zone between the support portion of the part and the stretched zone of the ornament are heated and stretched by a mechanical slide member, before the second step, with respect to the support and displaced in the stretched edge region.
The invention relates also to a device for carrying out the process with a movable support plate for maintaining a part which must be ornamented and coated with a multilayer ornamental material in its support portion, the part comprising an edge region, a grasping apparatus for grasping and firmly maintaining the ornamental material in a edge area of the corresponding part and with a heating apparatus for heating the ornamental connection in the region of said zone.
It is possible to provide that the plate has a cup shaped support surface.
Advantageously, the plate is movably mounted inside the machine so that it forms a stretching means that is arranged in the body of the machine by which the grasping apparatus makes possible a return of the sheet.
In a preferred embodiment of the invention, a second plate is provided, also in the forming device, in front of the first plate and arranged so that the part to be ornamented is confined between the first and second plates in order that the support of the part is near the first plate and the ornament near the second plate.
The heating device may be on the side of the sheet and/or on the side of the layer of foam.
It is also possible to provide a movable auxiliary forming element for stretching the ends of the ornament between the grasping apparatus and the plate(s).
In an other embodiment of the invention, it is provided that, on the side of the first or second plate, a pressure tight chamber is arranged for acting by suction or pressure on the deformation of the zone between the grasping apparatus and the edge region of the part.